The Laboratory Test Research Of Saturation Structured Soil On The Structural Strength

This paper studies on the marine mud soft clay in east China by artificially structured soils, direct shear test and consolidation test, and explores the influence of cement content on the cohesion and internal friction angle, as well as structural changes in the strength. Then based on the experimental data, it fits function using the MATLAB software, and builds the mathematical model among cohesion, internal friction angle and compressive yield stress. Meanwhile we got the conclusions as the following by the experiment:(1)The incorporation cement in different degrees can increase the frictional resistance and the knock-on effects among the soil particles. The cement solidification can also enhance the soil cohesion, cementation and inter-firm skeleton, thereby increasing the structural of the soft clay. That can well analog the structural of the undisturbed soil.(2)This paper introduces "yield ratio" concept which divides the structural clay into "fragile structure of soil" and "flexible structure of soil" via the strength. In the shearing process, "fragile structure of soil" is in elastic deformation stage, and shear stress changes linearly with the displacement of approximately. In the event of damage to the soil, the shear stress-displacement curve will show "collapse phenomenon of shear stress" clearly.(3)Structure yield stress may well reflect the soil structural. When the soil’s structural is low and is small, the structural impacts the internal friction angle φ more significantly; When the soil’s structure is high and is strong, the structural impacts the cohesion c more significantly. C is the exponential growth with, and φ is logarithmic growth with.(4)Soft clay is "fragile structure soil" in natural with a high sensitivity. In engineering practice, we should choose the appropriate ground treatment methods to minimize the "fragile structure of soil", and avoid uneven subsidence and safety hazards caused by the sudden destruction. This research has practical significance for engineering practice reference.